IDL compiler: merge and simplify EventHandler non-callable value check

Source/bindings/v8/V8Utilities.cpp

Index: Source/bindings/v8/V8Utilities.cpp
diff --git a/Source/bindings/v8/V8Utilities.cpp b/Source/bindings/v8/V8Utilities.cpp
index 71d7493b164bbc2aeb7128e7b8b2535ecaa7da6e..a395021305069b9835a6aa02c8ad4630434dd749 100644
--- a/Source/bindings/v8/V8Utilities.cpp
+++ b/Source/bindings/v8/V8Utilities.cpp
@@ -149,10 +149,8 @@ void transferHiddenDependency(v8::Handle<v8::Object> object, EventListener* oldV
                 removeHiddenDependency(object, oldListenerObject, cacheIndex, isolate);
         }
     }
-    // Non-callable input should be treated as null
-    if (!newValue->IsNull() && !newValue->IsFunction())
-        newValue = v8::Null(isolate);
-    if (!newValue->IsNull() && !newValue->IsUndefined())
+    // Non-callable input is treated as null and ignored
+    if (newValue->IsFunction())
         createHiddenDependency(object, newValue, cacheIndex, isolate);
 }